---
id: CVE-2026-102253
title: >-
  iperf3 versions prior to 3.22 contains a denial of service vulnerability that
  allows unauthenticated remote attackers to crash-loop the server's UDP receive
  worker into an unrecoverable infinite loop by sending a single crafted
  control-c…
summary: >-
  iperf3 versions prior to 3.22 contains a denial of service vulnerability that
  allows unauthenticated remote attackers to crash-loop the server's UDP receive
  worker into an unrecoverable infinite loop by sending a single crafted
  control-c…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-835
vendor: esnet
product: iperf3
affected:
  - iperf3 >= 3.14 < 3.22
published: '2026-09-29'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T21:17:13.640'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102253'
references:
  - url: 'https://github.com/esnet/iperf/blob/master/RELNOTES.md'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/esnet/iperf/releases/tag/3.22'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/iperf3-udp-receive-worker-infinite-loop-dos
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-29T20:46:06.617Z'
---

## Overview

iperf3 versions prior to 3.22 contains a denial of service vulnerability that allows unauthenticated remote attackers to crash-loop the server's UDP receive worker into an unrecoverable infinite loop by sending a single crafted control-channel parameter message followed by one 16-byte UDP datagram. Attackers can permanently pin the affected per-stream receive thread at approximately 100% CPU usage, rendering the server unusable until forcibly killed with SIGKILL, as the process does not respond to normal control-channel closure.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.